Milling rollers of the type set out above are known, for example, from EP 0 516 952 B1. They contain a plurality of wear-resistant profile-members which are embedded with a portion of the length thereof in holes of the roller body and protrude with the remainder of the length thereof above the surface of the roller body. When such rollers are operated, the intermediate spaces between the protruding profile-members are filled with the comminution material which is supplied to the material bed roller mill and which therefore provides a degree of autogenous wear protection for the surface of the roller body.
In the course of the operating time, both the protruding profile-members and the surface of the roller body are subject to unavoidable wear which makes reconditioning the milling roller necessary if the roller body is intended to be used further.
DE 196 18 143 A1 discloses a milling roller, wherein the hardness of the material of the roller body forming the roller surface is greater than 56 HRc (Rockwell hardness). This milling roller is used in comminution operation until a substantial portion of all the profile-members has become completely worn and/or has fallen out of the roller body. The reconditioning of the used milling roller is then carried out in such a manner that the roller surface has a cylindrical shape conferred on it again by complete turning of the profile-members and the original holes, after which new holes are produced and new profile-members are introduced into those holes.
Although it is possible in this known solution for the surface to wear substantially only to the same extent as the protruding profile-members by using an extraordinarily hard base material for the surface of the roller body, the complete turning of the surface of the roller body provided with holes involves substantial complexity owing to the great hardness of the surface material when a used milling roller of this type is reconditioned.
A prior German patent application (DE 10 2006 028 546 A1) further relates to a method for reconditioning a used milling roller of a high-pressure material bed roller mill, containing a plurality of profile-members which are embedded with a portion of the length thereof in holes of the roller body and, with the remainder of the length thereof, protrude above the surface of the roller body, with the profile-members having greater hardness than the surface of the roller body and the protruding portion of the profile-members and the surface of the roller body being at least partially worn. In this method for reconditioning, after the worn profile-members have been removed, the worn surface of the roller body is turned at least in a part-region of the width of the roller body as far as a diameter which is greater than the diameter of the base of the holes provided, after which
a) the holes provided are extended as far as a depth which is sufficient to receive new profile-members,
b) and/or new holes are produced in accordance with a new hole configuration,
c) and/or shorter profile-members are introduced into the holes which are now shorter.